Machinery for making crt electronic assemblies using two indexing tables

ABSTRACT

Apparatus providing for automatic manufacture of a portion of an electron gun in a cathode ray tube utilizes two conjointly operated indexing tables with an intermediate transfer mechanism to assemble, fit, stake and weld in place a series of parts. At a series of indexing positions parts are loaded, checked and processed with such manufacturing steps as cutting, positioning and welding a lead tab to a cathode cylinder. The use of two tables permits high strength for staking operations, greater production in a given time, and accessible layout of equipment in a small space.

United States Patent Merchant [451 Mar. 21, 1972 [54] MACHINERY FORMAKING CRT ELECTRONIC ASSEMBLIES USING TWO INDEXING TABLES [72]Inventor: Chester 0. Merchant, Owensboro, Ky.

[73] Assignee: Kentucky Electronics Inc., Owensboro,

[22] Filed: Mar. 4, 1969 211 Appl. No.: 804,077

52 us. Cl... ..29/2s.19 [51] Int. Cl .H0lj 9/06, H01j 9/10, l-lOlj 9/46[58] Field of Search ..29/25.2, 25.19, 25.13, 25.14,

[56] References Cited UNITED STATES PATENTS 3,130,031 4/1964 McMahon,Jr. et a] ..29/25.19 X 3,526,955 9/1970 Cilione 1,801,108 4/1931 Reufelet al... 1,947,610 2/1934 McNamara... 1,953,492 4/1934 May ..214/1 BC X2,394,700 2/1946 Jorgedyk ..72/ 306 2,605,537 8/1952 Pityo et a1.......228/l5 X 2,844,917 7/1958 Caldwell ..214/1 BC 3,047,166 7/1962 Lompet a]... ..214/] BC 3,247,355 4/1966 Olsen ....228/47 X 3,321,606 5/1967Cropp et al.. ..228/5 X 3,357,621 12/1967 Bodini et al.. ..228/473,395,845 8/1968 Best et al. ..228/47 X Primary Examiner-John F.Campbell Assistant Examiner-Ronald .1. Shore Attorney-Laurence R. Brown[5 7] ABSTRACT Apparatus providing for automatic manufacture of aportion of an electron gun in a cathode ray tube utilizes two conjointlyoperated indexing tables with an intermediate transfer mechanism toassemble, fit, stake and weld in place a series of parts. At a series ofindexing positions parts are loaded, checked and processed with suchmanufacturing steps as cutting, positioning and welding a lead tab to acathode cylinder. The use of two tables permits high strength forstaking operations, greater production in a given time, and accessiblelayout of equipment in a small space.

5 Claims, 27 Drawing Figures SHEET UIUF 17 FIG. I

r I"? w DROP LOAD 4| CATHCDE INVENTOR CHESTER 0. MERCHANT FIG. 2

ATTORNEY PATENTEDMAR 21 I972 PATENTEDHARZI I972 SHEET GQUF 17 INVENTORCHESTER O. MERCHANT ATTORNEY PAIENTEDMAR2I I972 SHEET .05 0F 17 FIG. I0

FIG. 9

FIG. l4

INVENTOR CHESTER O- MERCHANT ATTORNEY PATENTED MAR 21 I972 SHEET OBUF 172O INDEX CSI FIG. 27

a m a INVENTOR CHESTER O- MERCHANT ATTORNEY PATENTEDMARZI I972 3,650,002

SHEET over 17 FIG. l3

'INVENTOR CHESTER O. MERCHANT 345 BY 6Q ATTORNEY PATENTEDHARZI I9723.650.002

SHEET 08 0F 17 I INVENTOR CHESTER O. MERCHANT LEM 62 @W ATTORNEYPATENTEDMARZI I972 3,650,002

SHEET 09 or 1'! FIG. I7

INVENTOR CHESTER 0. MERCHANT BY MQBVM ATTORNEY PATENTEDMARZI m23,650,002

SHEET IUUF 17 FIG.

INVENTOR v CHESTER O. MERCHANT ATTORN EY PAIENTEUMARZI I972 3,650,002

SHEET 11UF 17 FIG, I9

INVENTOR CHESTER O- MERCHANT ig ww (Q ATTORNEY PATENTEDMARZI m2 SHEET120F 17 FIG. 20

- INVENTOR CHESTER O. MERCHANT ATTORNEY PATENTEDMARZI I972 SHEET 13 0F17 mu uE INVENTOR CHESTER O. MERCHANT ATTORNEY PATENTEDMARZI I972 SHEETNUF 17 N E V W CHESTER O. MERCHANT ATTORNEY PATENTEDMARZI I872 y3.650.002

sum lSUF 11 7 FIG. 24

INVENTOR CHESTER QMERCHANT ATTORN EY INDEX TABLE INDEX TABLE MOTORCONTROL PATENTEDMARZI I972 SHEET 17 A2 Al F2 DC MOTOR TERMiNDLS CERAMICCSI 4 MSI 5 SQL. AR VALVE LOADER REEET cm 16' 6 1 l d csgmi 8 cm 9 M 2%,CIO MSL Q 4'6 CATHODE cs4 |2 $01.. c.v vE LOADER 055 1 I SOL AIR (7AM EL454; "CR4! R- 2 '4,9(2osv) -LL."j H .9 H TAB FEED R4 a S 18 50.1.. IWELD CLUTCH RIBBON M86 l9 DETECTION "'fi CR5 STATION i F RE CR-6 16,1123 i |.HH{-@ I820 STOP CWISTART CR-ICRS (JR-6 H CR-T w FIG.26 mwm-INVENTOR CHESTER O. MERCHANT ATTORNEY MACHINERY F OR MAKING CRTELECTRONIC ASSEMBLIES USING TWO INDEXING TABLES SPECIFICATION Thisinvention relates to automatic machinery for manufacturing electronicparts and, more particularly, it relates to machinery for manufacturinga cathode ray tube electron gun assembly having a plurality of partsprecisely positioned.

Automatic machinery has been developed for assembling complex electricalassemblies such as tube sockets where a variety of parts feeding,welding and staking operations take place upon an indexing table.However, these are not suitable for the precision operations required inassembly of parts for a cathode ray tube gun, which demand criticaltolerances, alignments, and lack of any burrs or scratches to preventreject of an assembled tube costing many thousands of times the cost ofthe individual gun parts. The requirements for mechanical accuracy areeven greater in color picture tubes, since an interrelated action inalignment and performance is required among three separate electron gunassemblies. Because cathode ray tubes operate at high voltages, criticalcontrol is necessary to avoid scratches and burrs or any other defectthat might cause corona, arcing or X-ray emission. Thus, a real problemis presented in developing machinery which will be fast, accurate andgentle in its assembly of electron gun parts.

7 The extremely close tolerance requirements cause additional mechanicalproblems in the machinery, since wear, runout and sources of dimensionerrors must be carefully controlled. This is particularly true when manyrelated assembly and manufacturing steps are to be accomplished insequence in a short period of time. The nature of the finished electrongun subassembly requires that as many steps be accomplished as possiblewith a known orientation and co-relationship of the parts to avoidquality control variations presented by random orientation of parts whenhandled at intermediate steps. Thus, for example, a slightout-of-roundness from a given die or stamping operation may be tolerableif oriented in proper relationship to surrounding parts, but may resultin an operational reject if oriented differently in different guns asmight occur with manual transfer of partially manufactured parts. fromone machine to another during operation. These problems are acceleratedas processing speeds increase and are particularly critical in thecathode-grid portion of the electron gun.

It is therefore a general object of this invention to provide automaticmachinery for assembling parts in the manufacture of an electron gunassembly.

An object of the invention is to precisely control the location andorientation of parts in an electron gun cathode assembly.

Another object of the invention is to provide machinery overcoming theforegoing deficiencies and problems.

A further object of the invention is to provide automatic machinery formanufacturing electron gun subassemblies with high accuracies over longperiods of time and at high speed.

Thus, in accordance with this invention an automatic machine is providedfor manufacturing electron gun subassemblies, such as cathode mounts, byfeeding a plurality of interrelated parts into position for staking,shaping and welding operations forming an integrated subassembly. Themachine comprises a set of two cooperating index tables of smalldiameter, each with multiple stations, thereby to perform a series ofoperations, with relatively low peripheral speeds and high mechanicalstiffness as compared to a single table of large diameter thereby beingsubjected to less deflection and wear in the presence of staking andwelding operations. By alternately phasing operations at the two tables,high average productivity of finished parts per unit time is attainedwithout pushing individual operations or imposing critical timing andloading effects. A set of initial parts is fed to various indexingstations located on both tables for positioning and integrating into acompleted assembly, which in partly processed form is passed from oneindexing table to the other in a known and controlled orientation forreceiving further processing steps.

Because of the two co-related indexing table configuration a machine isproduced with accessible submechanisms at each indexing positionoriented to take up little overall space.

Further aspects of the invention, its merits and objectives are foundthroughout the following specification and accompanying drawings,wherein:

FIG. 1 is a plan view sketch of the overall indexing table assembly ofthe automatic machine as adapted in the illustrated embodiment formanufacture of cathodes;

FIG. 2 is a flow chart diagram of the operational steps performed inthis embodiment in the manufacture of a cathode assembly;

FIGS. 3 and 4 are respectively elevation and plan views, partly insection, of a transfer mechanism for placing a part on the indexingtable;

FIGS. 5 and 6 are respectively elevation and plan views, partly insection, of a ceramic disc transfer assembly;

FIGS. 7 and 8 are respectively elevation and plan views, partly insection, of a disc transfer shuttle mechanism operable with the transferassembly of FIG. 5 to place a ceramic disc in place upon the indexingtable;

FIG. 9 is an elevation view, partly in section, of a fixture assemblyfor fitting into the first indexing table;

FIGS. 10 A and B are fragmental section views of a partially stakedceramic disc assembly at different stages of manufacture;

FIG. 11 is an elevation view, partly in section, of a staking punch unitfor affixing a ceramic disc upon a cathode sleeve;

FIGS. 12 and 13 are respectively elevation and plan views, partly insection, of a mechanism for transferring a partly manufactured part froma fixture assembly on one index table to another;

FIG. 14 is an elevation view, partly in section, of a fragmental view ofthe fixture assembly fitting into the second indexing table;

FIG. 15 is an elevation view, partly in section, of the mechanism forloading a cathode tube 10 into a partially manufactured part on thesecond indexing table;

FIG. 16 is an elevation view, partly in section, of a welding mechanismoperable to weld assembled parts together;

FIGS. 17 and 18 are respectively elevation and plan views of a ribbontab feed assembly;

FIG. 19 is an elevation view of a tab welding assembly;

FIG. 20 is an elevation view, partly in section, and FIG. 21 a plan viewof a mechanism removing an assembled part from the indexing table;

FIG. 22 is an elevation view of the assembled machinery in a bencharrangement;

FIG. 23 is a plan view of a camshaft arrangement directing operationsequences of the various mechanisms;

FIG. 24 is a plan view of a supplementary camshaft arrangement for thetab feed mechanism;

FIG. 25 is a cam timing chart'showing relative operation times for eachof the mechanisms;

FIG. 26 is a schematic circuit diagram of a control circuit foroperating the machinery described herein; and

FIG. 27 is a timing diagram for electrical switches driven from the maincamshaft.

The general operation is referenced to FIGS. 1 and 2 showing themachinery layout and the functional flow chart for operation. Thecathode mount subassembly portion 9 of a cathode ray tube electron gunis manufactured by the automatic machinery embodiment described. Thiscathode comprises a set of pre-manufactured parts including the closedend cathode cup 10, and an intermediate mounting shield or sleeve 11between it and a ceramic disc 12. A shoulder 14 is provided on thesleeve 11 for holding the ceramic disc 12 in place about the neck 15after it is dropped into position from the phantom position 12' shown.The neck is rolled over to provide a clamp 16 holding the ceramic discin place. The operations just described take place on a first indextable mechanism 20.

The partially completed subassembly 18 is then turned over andtransferred into position on a second indexing table 40, where it isheld in place for insertion of cathode cup 10, which is welded in placecoaxially within sleeve 11. A tab 19 is then cut from a roll and weldedonto the sleeve 11, after which the assembly is removed from the secondindexing table 40. Typically, the diameter of the ceramic disc 12 isabout threeeighths of an inch with the other parts proportionatelydimensioned.

Each of the indexing tables 20, 40 of this embodiment have a pluralityof stations for convenience in this view shown as six stations numbered21-26 and 4146 respectively in the order of their processing a cathodemount from its initial part insertion to the removal of the completedcathode mount subassembly 9. The tables are commonly driven insynchronism to rotate, index and halt for an operation at a speed of theorder of 1 cycle per second, which therefore produces a completedsubassembly each second at the final discharge station.

At station or position 21 on the indexing table 20, sleeves 11 areloaded to slip over a fixture assembly located at station 21, thedetails of which may be observed in FIG. 9. The sleeves 11 are fed bymeans such as an orienting vibrator bin 50 into a slide chute 51orienting the sleeves into a limiting position where pivoting arm 52grasps and moves them into place to drop on to the fixture assembly atstation 21. This part of a particular mechanism is shown in detail inFIGS. 3 and 4.

At a further time in the cycle, the indexing table 20 moves the part 11into position at indexing station 22. In this position a ceramic disc ismoved from bin 60 down cute 61 to the position 62, where it istransported by means of the rotating, lifting and lowering shuttlemechanisms 63, 64 to station 22.

From this position the indexing table moves the sleeve 11 with disc 12resting on shoulder 14 on to station 23 where staking tool 70 operatesto give a first bend or curl to the lip 15. Thereafter at station 24 asecond bend is given to complete the roll-over clamp 16. The fixtureassembly is shown in FIG. 9, the two steps of bending the sleeve 12 inFIG. 10, and the staking stations in FIG. 11. In FIG. 9 it is shown thatthe anvil 126 which is affixed to the holder clamps 127, 128 fits intoregistration holes in the indexing table by posts 129. The anvil ishollow as shown, and provides for the sleeve 11 and disc 12 to restthereover.

At the first curling station 23 the sleeve 11 is rolled over as shown inFIG. A by an appropriate die 212 drawn in place over the anvil of FIG.9. At the next station 24, a further curling die is moved to bend thelip 130 under while the top of the loop 131 is pushed down to provide aclamp that is resilient giving a spring action in holding the shoulder14 tightly against disc 12, as shown in FIG. 108, without putting enoughpressure upon the thin, fragile, ceramic disc 12 to crack it. Theoperation of the bending at stations 23 and 24 is later described alongwith FIG. 11.

At this stage of manufacture there may be certain scratches or dimplesintroduced from the tools which can be oriented for location in thefinished part to avoid rejects, but which if randomly oriented, couldintroduce in some cases enough cumulative tolerance variations to causeoccasional reject of an expensive completed color picture tube. Thus,while it is possible to transport parts manually from one fixtureassembly station to the next, it is preferable to retain full control oforientation and provide for a mechanical transfer even between the twoindexing tables 20, 40 as shown by transfer mechanism 140. This servesto lift, turn and lower the staked sleeve-disc assembly 11-12 at station41 onto a fixture assembly on the second indexing table 40. The transfermechanism 140 is described later in connection with FIGS. 12 and 13.

After transfer of the part between tables, a detector may be used atstation 42 to assure that a part is in proper position before furthersteps are taken. Responsive to a detection signal that a part is not inplace, the machine may be halted or one or more of the succeedingoperations may be eliminated by means of programmed clutches or thelike. Each table may be indexed to twelve different positions with acheck station between each of six operational stations such as numberedon FIG. 1, if desired. At station 43, the cathode cylinder 10 is loadedinside sleeve 11 in which it fits frictionally with a sliding fit to bedisposed to extend the appropriate distance from the ceramic disc toestablish proper grid spacing. Thus, cathode cylinders 10 are fed closedend down (FIG. 2) in chute 91 from bin 92 to be transferred by arm tothe index station 43 where they are inserted into the sleeves 1 1. Intable 40, the fixture assembly is similar to that hereinbefore describedexcept that a different anvil 132 as shown in FIG. 14 is adapted toreceive the parts after being inverted onto the second indexing table40. The spacing of the cathode is determined by the limiting stop member133. As shown in FIG. 15, the part is held by suction while beingtransferred into position by movable lever arm 90 traversing over thedesignated angle as shown in FIG. 1.

After the cathode 10 is inserted and positioned within sleeve 11, theassembly is moved into station 44, where the cathode 10 is welded to thesleeve 11 in an exactly predetermined position by four welded spotspositioned about the periphery. The welding assembly is shown in FIG.16, which is described hereinafter.

For the application of tab 19, feeder and welder assembly is provided atstation 45. FIGS. 17 and 18 relate to the tab feed assembly and thewelder assembly is shown in and described in connection with FIG. 19.

The terminal station 46 serves as a discharge station where mechanismremoves the manufactured assembly from indexing table 40. This mechanismis shown in FIGS. 20 and 21. Each mechanism used in manufacturing acathode assembly is described separately, but it is to be understoodthat the manufacturing stations or their number may be altered toprovide different or supplemental operations, and that differentelectronic parts or cathode structures may be made by similar operationswithout necessarily departing from novel principles afforded by thisinvention.

As may be seen from FIGS. 3 and 4, the transfer mechanism removes a part11 from the end of feed chute 51 and places it onto the first indexingtable for processing. The mechanism operates in a rotate and lift modeat a time synchronized to meet a station in theindexing table inresponse to instructions received from a set of timing cams to bedescribed later. Thus, the previously described pivot arm 52 rotatesabout an angle a (FIG. 1) with shaft 53 to which it is clamped by bolts59. The shaft is rotated by a lever arm cam arrangement coupled torotating arm 54. As this arm is rotated about bearings 152, theextension slide 156 contacts arm 157 and rotates it and the shaft 53affixed by pin 151.

The shaft is raised and lowered along slide 156 as indicated by arrow158'by cam lever rollers riding in a groove within the collar 255, whichpushes the shaft up and down by force of gravity downward, in bearings56 and 57 to oscillate within housing 58. The entire assembly may bemounted on a bench 159.

The mechanism undergoes a cyclic operation of grasping a part 11 fromchute 51, lifting the arm 52 over the index table, lowering the shaft todischarge the part on the index table over an anvil 126, lifting andreturning to grasp another part.

A guide arm 154 is attached to housing 58 by screws 153 and serves tosupport track end 51 and pivoted arm 258 to which is attached sleevelocator block 259. The position of the pivoted arm is dictated by a cam258A. Thus the sleeve locator block is positioned in front of track end51 during the period when arm 52 is rotated clockwise to lead part 11.When arm is rotated counterclockwisesleeve locator block is movedclockwise to permit jaws 155 and 156 to engage and lift part 11 withoutinterference by parts in track end 51 and the preceding chute.

Rocker arm 250 disposes a plunger 251 which pushes part 11 from thefrictional grasp as the arm 52 is moved downward over the indexing tableand shaft 253 registers with adjustable bolt head 254 upon reciprocationof the shaft 53. This permits

1. Apparatus for automatically manufacturing subassemblies for cathoderay electron tube guns including a tubular cathode electrode, comprisingin combination, an indexing table arrangement of small diameter toproduce a short lever arm from the outer periphery to the pivot shaftwhereby high strength is provided for staking operations, little spaceis Occupied and critical tolerances are maintained over long periods ofoperation, said indexing table arrangement providing near thecircumference of the table a plurality of positions and means indexingthe table to carry an electron gun part from position to position,mechanical means loading an apertured ceramic disc on the indexing tableat one position, mechanical means locating a cathode electrode parthaving an open end in the form of a cylinder into the apertured ceramicdisc, and staking means at a position about said indexing table rollingover said open end to contact said disc and clamp said electrode part tosaid disc while resident at said one position on said table. 2.Apparatus as defined in claim 1, wherein said electrode part comprises acathode sleeve cylinder with a shoulder intermediate its ends, and meansholding the shoulder against said disc while said staking means rollsover said open end.
 3. Apparatus as defined in claim 1, wherein saidindexing table arrangement comprises two side-by-side indexing tablesand a sequence of positions starting on one table and ending on theother table each adapted to form an intermediate manufacturing step onsaid subassemblies.
 4. Automatic machinery for manufacturing electrongun subassemblies from a set of electrode parts including ceramic andmetallic parts, comprising in combination, a plurality of at least twocoacting rotary indexing tables each having a multiplicity of specialpurpose indexing positions for processing one of said parts, at leastone of said indexing positions on one table provided with impact meansto shape one of said metallic parts while resting on the table, andhaving a table diameter small enough to produce a short lever arm fromthe outer periphery to the pivot shaft whereby high strength is providedfor the impact operations, little space is occupied by the indexingtable and critical tolerances are maintained over long periods ofoperation, a station adapted for receiving a first part for processing,and means indexing said part successively through a plurality ofpositions on each of said indexing tables, including a mechanismtransferring the part from one table to the next wherein the electrongun subassemblies manufactured are cathode assemblies including acathode cup member, and said automatic machinery includes means locatedat separate stations alongside said indexing tables to handle andintroduce to positions on the two said tables a plurality of differingparts of said cathode assemblies.
 5. Machinery as defined by claim 4,including receptacle means located at a specified station adjacent oneof said tables for receiving a manufactured subassembly as the part isrotated by said table into receptacle structure comprising a graspingarm, means including an inclined plane for discharging the part fromsaid grasping arm, and means rotating the grasping arm into contact withsaid inclined plane from said specified station.